Research Status on Nonlinear Transmission Lines for RF Generation

Abstract

High power RF generation using alternative methods based on a non-conventional technique has been investigated recently. In general, conventional based-tube RF generation requires vacuum and heating filament, which consumes space and power. In our research, it is envisaged the use of nonlinear transmission lines (NLTLs) to replace the RF tubes in several applications as these new devices are all solid-state. For instance, lumped NLTLs can be used in the disruption of battlefield communications and drone telecommands as well in SAR radars for image remote sensing. There are two types of NLTLs: lumped lines with at least one nonlinear component (L or C) and nondispersive continuous ferrite loaded lines biased by an external axial magnetic field, known as gyromagnetic. With lumped NLTLs, our ongoing experiments have shown the operation of these devices at 300 MHz, using SiC Schottky diodes with a pair of DRG antennas for propagation <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> . With gyromagnetic lines, the recent results have demonstrated that these lines can also operate in the lower band range <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (200 MHz). For future tests, it is expected that these lines will reach operation frequencies up to 1.5 GHz using permanent magnets for compact space applications.